DynamoDB provides Query and Scan operations, for querying and browsing.
For each navigation, GeneXus uses the most appropriate operation.
Note that every navigation must have an order compatible with one of the table indexes (either the PK index or one of the Duplicate indexes). The PK index is associated with the Primary Key of the DynamoDB Table. Duplicate indexes are associated with the Secondary Indexes of the DynamoDB Table.
The first attribute of the index in the dataview is the Partition Key, and the second is the Range Key (if it exists).
To be able to sort, the PartitionKey should also be instantiated (this is a DynamoDB requirement).
When sorting by Primary Key, the specifier does not require the PartitionKey to be instantiated. However, if it is not instantiated, the result will NOT be sorted.
If the order cannot be resolved, the message spc0116 will be displayed.
The web interface of any Transaction usually offers navigation buttons to view the records (next, previous, last, first). With DynamoDB, it is not possible to sort the records if the PartitionKey is not instantiated. Therefore, these navigation buttons will not work properly by default because if the data is not sorted, the "next" record of a given record cannot be calculated correctly.
The filter conditions are evaluated in DynamoDB after running the Query but before returning the data. If the specifier determines that the condition cannot be evaluated in DynamoDB, it is marked with an exclamation mark (!) in the navigation diagram of the object. Lastly, the client evaluates whether each record meets the filter criteria, as in any other DBMS.